Like going over the Niagra Falls in a barrel, there are plenty of things that are difficult to do – and a bit pointless – but it is cheering that somebody is daft enough to do them. Building an Audi S8 Plus is just such an exercise in extreme inanity.

And it is one thing to be insanely quick on an Autobahn, but we tried the new S8 Plus on country roads in the UK. Does it hold together between the hedegrows?

So why do I need one of these?

For those not aware, or for the very few aware enough to finding the standard and very scarce Audi S8 a bit mealy, the Plus version has increased power to 597bhp from 513bhp – while peak torque is up to 553lb ft, from 479lb ft.

The result is that very rich people will now go from sitting still to 62mph in 3.8 seconds, instead of 4.1sec, and will find their cossetted bottoms topping out at a restricted 155mph very soon after.

Should they like to make their bottoms go faster, they can opt for the optional Dynamic package which will allow for a 189mph top speed, and add ceramic brakes too.

Compared to the standard S8, the Plus’s powerplant has been extensively modified to boost its performance. It features special engine management software, modified exhaust valves and turbocharger upgrades.

So it is pretty quick then?

The result of this hike in power and grunt is that you go very, very fast, very very quickly. It’s disconcertingly quick, with a rather distant V8 roar accompanied by seamless changes and drivers behind disappearing very quickly, while the Quattro system obviously aids in the rapid deployment of fresh air between you and everyone else on the road. This is exactly what you would have paid for.

Of course, once you reach tighter roads and bends, the whole thing becomes more unseemly because the Audi is massive and heavy. While it still will leave most cars on the road for dead, it does it in a brutal and effective way, rather than in an especially enjoyable manner. It’s not its job to deliver B road thrills, after all.

It’s a little odd, then, that the S sports adaptive air suspension – which has been tuned specifically for the S8 Plus – and standard 21-inch alloy wheels deliver a ride firmer than you might want from your motorway wafter. You can feel small ridges in the road, even through many inches of leather and carpet.

Is it noticeably quicker than an S8 though?

Well, it’s a bit like wondering if your plummeting barrel has picked up more speed than the last plummeting barrel you were curled up in. Such is the incredible quality of the interior (S8, rather than barrel), that very high speed just becomes another daily element of the car, like the amazing Hi-Fi or the beautifully tailored seats.

And it’s not immediately different from that car in looks either. Darkened tail lights and a rear lip spoiler in body colour are pretty much all that show it to be different. You can specify, however, carbonfibre wing mirrors and a carbonfibre rear spoiler, as well as a matt silver paint finish.

So should I go for the Plus rather than the standard S8?

If you’ve got to this point, then why the hell not? An S8 is a very, very lovely thing, if an anachronism. Why not just have the diesel A8 so you have to stop less, and have fun in your various sports cars when the mood arises? But if you must, then why not splash an extra £16,000 on the magnificently mad Plus. After all, logic has long since gone out the window.

Verdict

By any measure that makes sense, the S8 Plus makes no sense. But it is a wonderful machine: brutally fast and beautifully built.